KIEV, Dec. 3 - Ukraine may permanently close its largest coal mine, Zasiadko, after the third methane explosion over the past two weeks killed five coal miners late Sunday, Prime Minister Viktor Yanukovych said Monday.

Zasiadko, the major producer of coking coal used in the steel industry, is the site of Ukraine's worst mining accident when a similar gas explosion two weeks ago has killed 101 miners. A less powerful explosion on Saturday injured 47 miners.